The present invention relates to a process for improving the yield of high octane number gasolines. More specifically, the present invention relates to a process for increasing the yield of high octane gasolines produced during the naphtha reforming step.
Naphtha reforming is a well known process used to improve gasoline quality. The naphtha fraction has a boiling temperature between 80 and 200.degree. C. and essentially contains paraffins, naphthenes and aromatics. The most important reaction occurring during naphtha reforming consists in the dehydrocyclization of the paraffins into aromatics. It is well known that catalytic reforming tends to increase the final boiling point of the reformate (compared to the naphtha) and to favor benzene formation. Moreover these phenomena are more marked since low pressures (about 1MPa or less) and high temperatures are often used. However, among the requirements regarding reformulated gasolines, it is known that the final boiling point of the reformate must be sufficiently low and the benzene content limited.
It has now been discovered that it is possible to significantly improve the high octane gasoline yield and to solve the above-identified problems.
The object of the present invention is to provide a process which increases the high octane gasoline yield, i.e. the intermediate fraction coming from the naphtha reforming step.